1. Technical Field
The present invention relates generally to robotics and more specifically to telepresence systems.
2. Background Art
In the past, video camera and audio systems were developed for improving communication among individuals who are separated by distance and/or time. The systems and the process are now referred to as “videoconferencing”. Videoconferencing sought to duplicate, to the maximum extent possible, the full range, level and intensity of interpersonal communication and information sharing which would occur if all the people or meeting participants were “face-to-face” in the same room at the same time.
In robotic telepresence, a remotely controlled robot simulates the presence of a user. The overall experience for the user and the participants interacting with the robotic telepresence device is similar to videoconferencing, except that the user has a freedom of motion and control over the robot and video input that is not present in traditional videoconferencing. The robot platform typically includes a camera, a display device, a motorized platform that includes batteries, a control computer, and a wireless computer network connection. An image of the user is captured by a camera at the user's location and displayed on the robotic telepresence device's display in the surrogate's location.
The position of a person can be considered as the combination of two components: their position in an x,y plane (and z if multistory buildings are considered), and the direction a person is facing (e.g., an orientation angle relative to compass headings). As part of recreating the experience of being in a surrogate's location it is desirable to allow the user to control their position at the surrogate's location as immersively as possible.
Unfortunately, teleoperated mechanical motion is slower than that achievable by a physically present person for several reasons.
First, the communication and computational delays between the user and the surrogate mean that if the surrogate moves quickly it is likely to overshoot the desired motion of the user. For example, the user may command the surrogate to stop rotation when the user sees the desired heading has been achieved at the surrogate's location. However, the video display to the user is delayed by a significant fraction of a second over reality, and it also takes a significant fraction of a second to send the commands from the user to the surrogate and for them to take effect. If the surrogate is rotating at human speeds (e.g., 180 degrees a second), combined round-trip delays of only one-half second can result in an overshoot of 90 degrees.
Second, surrogates tend to be heavier than a person and so have more inertia. Thus it requires a lot of power to accelerate and decelerate them quickly.
Third, rapid teleoperated motion requires more automatic safety safeguards to avoid injury or damage to persons or property.
Previous teleoperated surrogates have required remote rotation of the surrogate body for steering when moving to new locations, and remote rotation of the surrogate's head for changing the orientation of the user's head at the surrogate's location.
This suffers from the feedback lag problem and other problems mentioned above.
Solutions to problems of this sort have been long sought, but have long eluded those skilled in the art.